docs: def add_event_callback(channel, callback, bouncetime=None):
      """
      :param channel: the channel based on the numbering system you have specified
          (:py:attr:`GPIO.BOARD`, :py:attr:`GPIO.BCM` or :py:attr:`GPIO.SUNXI`).
      :param callback: TODO
      :param bouncetime: (optional) TODO
      """
      _check_configured(channel, direction=IN)
  
      if bouncetime is not None:
          if _gpio_warnings:
              warnings.warn("bouncetime is not (yet) fully supported, continuing anyway. Use GPIO.setwarnings(False) to disable warnings.", stacklevel=2)
  
      pin = get_gpio_pin(_mode, channel)
      event.add_edge_callback(pin, __wrap(callback, channel))